Science News for the Week, Aug 6-12
August 13, 2011 - Saturday
Too much good stuff!
• This week marks the 20th anniversary of arXiv, the open access online database of research papers for physics and related fields. It's hard to underestimate how arXiv has revolutionized and democratized the distribution of knowledge in physics. In a great article, the founder Paul Ginsparg reflects on two decades of sharing results rapidly online and discusses its future. It will be interesting to see if the other physical sciences follow the example of physics in the coming years.
• There was a lot of hoopla this week about SETI (the search for extraterrestrial intelligence) coming back online after donors contributed over $200,000. Besides providing an opportunity to gain some media attention, it's not clear to me what the big deal is. This amount of money is not much when you consider that the Allen Telescope Array costs millions of dollars a year to operate. Just as a comparison, in the same time period Zach Weiner and friends have raised over $70,000 for a video webseries (which should be awesome by the way).
• After 3 years and 13 miles, the rover Opportunity reached the rim of a new crater it will be exploring on Mars (yeah, traveling around on Mars is a little slow). The crater is older than where Opportunity explored before, and there is evidence for clay sediments that may tell us something about the early history of the planet. Opportunity will probably continue to explore this crater for the next few years until it goes kaput.
• The satellite PAMELA found evidence for a belt of antiprotons circling the Earth. This has long been theorized, but this is the first confirmation. Antiprotons are just like protons, but with opposite charge. Every particle has an antiparticle pair, and the two annihilate each other when they come into contact. When high energy particles (like those coming from the Sun) strike the Earth's atmosphere, they sometimes create antineutrons which decay into antiprotons and are then trapped by the Earth's magnetic field. Here is a great summary of how this all works.
• There was a nice summary article on recent advances in using DNA to trace the history of humans. One of the most interesting results is that people of European and Asian descent may owe up to 4% of their DNA to Neanderthals. This interbreeding occurred around 65,000 to 90,000 years ago, about the same time when humans began migrating out of Africa. The breadth of information that can be inferred from genetics is pretty astonishing!
• Finally, there was a bunch of excitement today about an extrasolar planet that reflects almost no light. The planet was discovered by the Kepler satellite, which monitors a few tens of thousands of stars, looking for planets to cross in front of them. In this particular case, as the planet passed behind its parent star, astronomers could infer how much light it was reflecting and found only about one percent. This is crazy because even Mercury reflects like ten percent of the light that hits it. One explanation that is being discussed is that the planet's clouds (it's a gas giant like Jupiter) have a weird composition. It's amazing to imagine a planet that is basically a "near-black ball of gas, with a slight glowing red tinge to it."
August 8, 2011 - Monday
I've really been enjoying Darryl Cunningham's comics. For example, check out his work on climate change, evolution, and Andrew Wakefield. He's currently finishing up a comic on chiropractic therapy that I'm looking forward to.
Also, I have a few more Magic: The Gathering auctions on eBay ending this week. Please check them out if you're into that kind of thing.
Science News for the Week, Jul 30-Aug 5
August 6, 2011 - Saturday
Lots of great stuff to discuss.
• The Juno spacecraft had a successful launch Friday morning and is on schedule to reach Jupiter on July 4, 2016. I've discusses this satellite before, but here is a nice summary of 6 mysteries Juno may solve.
• There was a lot of buzz this week about some of the best evidence yet for water on Mars. To make a long story short, there are streaks that appear on Mars during late spring and disappear at the end of summer, which you can see in this animated gif. Our best explanation is that this is flowing water. Unfortunately, the next Mars rover won't be anywhere near this region, and it's in a very rocky terrain that would be hard to traverse. It seems unlikely we'll be able to test this hypothesis anytime soon. You can listen to more about this discovery on Science Friday.
• One of the big mysteries about the Moon is that the near side (which always faces the Earth) is very different from the far side (which always points away). There are compositional differences, the crust is thicker on the far side, and the near side is rather smooth while the far side is more rocky and cratered. In a paper released this week, theorists speculate that this may be explained if the Earth actually had two moons in the past. The Moon was formed when a Mars-sized body hit the Earth when it was very young. If a second moon was formed at this time, it could be a Trojan satellite to the Moon (just like how we discussed a Trojan satellite to Earth last week). Even though the second moon's orbit would initially be stable, over time, as the moons moved away from the Earth (which is something that is happening now as well due to tidal torques), the second moon would eventually get far enough away to be perturbed by the Sun's gravity and collide with the Moon. The theorists simulated this collision between the two moons, showing that it was plausible that the final body is something like the Moon we have today. You can hear more about this on Science Friday as well.
• Chinese paleontologists reported that a previously unknown chicken-size 155-million-year-old dinosaur with feathers may actually be a more direct ancestor of birds than Archaeopteryx. If confirmed by further research, this would indicate that Archaeopteryx was from a different evolutionary line than birds and should be thought of as strictly a dinosaur, supporting the idea that dinosaurs in general were much more bird-like than previously appreciated.
• Finally, I think I may have found evidence that the Higgs boson has been discovered. The website Paddy Power allows people to bet on a wide range of things, including whether the Higgs will be found. As more news about the Higgs has accumulated over the last few months, the odds have been shifting. Finally, when I checked the odds today, I saw this page saying they aren't allowing bets on the Higgs anymore. My hypothesis is that the researchers at the LHC found the Higgs, but before making the results public they bought a bunch of bets. Now they can cash in big time when the announcement is made. Maybe this is the solution to science's budget woes!
Science News for the Week, Jul 23-29
July 30, 2011 - Saturday
Just two quick items this week.
• The Juno spacecraft made its way to Cape Canaveral to prepare for a launch sometime between August 5th and August 26th. Juno will arrive at Jupiter in July 2016 and study a bunch of different stuff about the planet, including measuring the composition, probing the powerful magnetic field, and using a gravity-gauging system to measure the mass of the any rocky core at the center of Jupiter, which will be key for understanding its formation. I haven't had time to listen yet, but there is an interview about this mission on Science Friday today, which I'm sure is great. And while you're at the site, you might as well listen to the discussion on the next Mars mission, which is something I mentioned last week.
• In a paper released this week, astronomers announced that an asteroid discovered in late 2010 is the Earth's first known Trojan asteroid. Trojan satellites sit in one of the two stable points ahead or behind the planet's orbit. Instead of simply orbiting in a circle the Trojan oscillates in a complicated pattern, which you can see this cool movie. Previously, only Jupiter, Mars, and Neptune were known to have Trojans, with Jupiter famously having thousands of them. Paul Wiegert, who was one of the astronomers who made the discovery, has a helpful webpage if you'd like to learn more. You can again listen to a discussion with another one of the astronomers on Science Friday today.
Calm Blue Oceans and Other Items
July 25, 2011 - Monday
A few things to report on today.
First, I've really been enjoying the comic Calm Blue Oceans lately. Check it out, you may like it too.
Second, I'm auctioning a few Magic: The Gathering cards on eBay. Some of the auctions end today and tomorrow, but I'll be adding more items this week. If you're a serious collector, you may be interested.
Science News for the Week, Jul 16-22
July 22, 2011 - Friday
Lots of fun news this week, so let's get to it!
• This morning, at a physics conference in France, two groups that are doing experiments at the Large Hadron Collider announced that they had independently detected an unusual surplus of events in the mass range of 130-150 Gev. Could this be the elusive Higgs particle that physicists have long been searching for? In statistical jargon, this is only a 2.8 sigma result, so not nearly enough to be a real detection. But enticingly, a couple of months ago, data from the Tevatron showed an excess in a similar mass range. It will be fun to see what happens as more data is analyzed!
• Astronomers announced that they found a fourth moon orbiting Pluto, which you can see here (also here's a nice diagram of Pluto's system of moons). The New Horizons mission will be visiting Pluto in 2015, and this just adds to the interesting things that will be studied then.
• This morning NASA announced the choice of the landing site for the Mars rover Curiosity, which will be the Gale Crater. This is an interesting location, because it is at a very low elevation and could have been aqueous in the past. Also, there is a 5 km mountain of sediment in the crater and we may learn a lot from studying these old layers of material. Curiosity is set to launch near the end of this year, and will reach Mars in the fall of 2012.
• Scientists in Japan showed from measurements of antineutrinos released from the decay of uranium and thorium in the Earth's interior that about half of the heat coming from the Earth is due to radioactive decay. The other half is due to heat left over from formation and the solidification of the core. This heat is important for driving plate tectonics and has implications for the history of geologic activity on Earth. Ironically, this result was in part due to an earthquake in July 2007, which shut down a local nuclear power station. This decreased background events so that this measurement could be done more easily.
• Finally, this didn't get much news press, but I thought it was a neat result. A group of astronomers announced the discovery of a rare object called a collisional ring galaxy, which you can see in the picture below. It's formed when one galaxy basically slams through the center of another galaxy. When this happens, just like a pebble being thrown into a pond, it sends out a circular wave. But instead of a ring composed of water, this ring is composed of newly born stars that formed due the compression of material (here's an even more extreme example). Cool stuff!